1. Field
An embodiment of the present disclosure relates to an electronic device, and more particularly, to a semiconductor memory device and an operating method thereof.
2. Description of the Related Art
Semiconductor memory devices are generally classified into volatile memory devices and nonvolatile memory devices.
Non-volatile memory devices perform read/write operations at relatively low speed, but retain stored data even without a constant source of power. Accordingly, non-volatile memory devices are used in situations where data needs to be stored without a constant source of power. Examples of non-volatile memory devices include read-only memory (ROM), mask ROM (MROM), programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, phase-change random access memory (PRAM), magnetic RAM (MRAM), resistive RAM (RRAM), ferroelectric RAM (FRAM), and the like. Flash memories are classified into NOR type flash memories and NAND type flash memories.
Flash memories have an advantage of RAM in that data is freely programmed and erased, and advantages of ROM in which stored data is retained even without a constant source of power. Flash memories are widely used as storage mediums of portable electronic devices such as digital cameras, personal digital assistants (PDA), and MP3 players.